We propose to develop a low cost, moderate complexity molecular test for the detection of CT/NG intended for use at STD clinics. This test will use a manually operated nucleic acid extraction device, an isothermal amplification technology called thermophilic helicase dependent amplification (tHDA), a disposable nucleic acid detection device, and a reusable reader. Our proprietary tHDA uses helicases to separate DNA strands rather than heat but still relies on DNA polymerase to amplify DNA instead of combinations of polymerases with other enzymes. This simple enzymology allows us to detect DNA amplification inhibitors, allows for the confirmation that a legitimate product was amplified, and the quantitation of nucleic acids in a sample. No other isothermal amplification technology retains these highly attractive features. The projected cost for the two assays is ~$20. The advantage of using isothermal amplification is that equipment costs will be minimal (i.e., $200 water bath, and a ~$800 reader). We propose to focus our first project year on further evolving our proposed assay system by improving our reaction speed, improving our prototype sample preparation module, and demonstrating the feasibility of using an automated reader with the BESt cassette. In year 2, we will focus on the formal design control process, and transfer to manufacturing of our proposed assay system. We will develop a clinical study plan for review by institutional IRBs, and a pre-IDE for review by the Food and Drug Administration (FDA). In years 3 and 4 we will perform a multi-site clinical study to obtain data for the submission of a 510(k) to the FDA. We expect to obtain FDA clearance for the CT/NG assays by the end of the proposed project. In year 5, we will develop a clinical plan, and perform a pre-clinical study to evaluate the feasibility of obtaining CLIA-waiver for the assay system.